Change in pressure mattress



May 9, 1967 Filed 001;. 9, 1964 A. HINRICHS CHANGE IN PRESSURE MATTRESS Sheets-Sheet 1 INVENTOR flhnol d v Hinds/is ATTORNEYS May 9, 1967 A. HINRICHS 3,317,934

CHANGE IN PRESSURE MATTRESS Filed Oct. 9, 1964' 2 Sheets-Sheet 2 DOUBLE ACT/0N PUMP INVENTOR M M/ A'ITO EYS CHANGE IN PRESSURE MATTRESS Arnold Hinrichs, Luheck, Germany, assignor to Otto Heinrich Driiger, Luheck, Germany Fiied Oct. 9, 1964, Ser. No. 402,811 (Ilaims priority, application Germany, Oct. 24, 1963, D 42,794 3 Claims. (Cl. 349) This invention relates to a change in pressure mattress and, in particular, to a pulsating bed mattress.

So-called change in pressure mattresses are known which are composed of several separate flexible air chambers into which air is alternately pumped so that one set of air chambers is inflated while the other set of air chambers is deflated. These separated air chambers are usually combined into two sets of chambers, each in a closed system and with the chambers being evenly distributed across the surface of the mattress. For example, the mattress is composed of tubes parallel to each other and with alternate tubes combined into a system forming a set of air chambers. Other methods of construction are also used. The two sets of air chambers can be connected to the opposite sides of a double-action air pump.

Also, each set of air chambers have been actuated by an electrically driven air pump which is switched on and off by an alternating switch. Furthermore, the air valves for the change in pressure mattress can b electrically controlled.

The object of this invention is to improve upon the construction and operation of the known change in pressure mattresses.

In this invention, the separate sets of chambers are filled with liquid and connected to pump means for the reversal of the flow of liquid through the alternate sets of chambers. Heat exchanger means are employed for each set of chambers. This has the advantage that the mattress can be maintained at a predetermined temperature. Heat can be introduced into the liquid for heating the mattress, and likewise, the liquid can be refrigerated to cool the mattress.

A separate pump can be provided for each set of chambers, respectively. In a modified form of the invetnion, the liquid pump is a double-action piston pump in which each set of chambers is in communication with a separate cylinder of the pump.

The means by which the objects of the invention are obtained are described more fully with reference to the accompanying drawings in which:

FIGURE 1 is a schematic view of the apparatus of this invention;

FIGURE 2 is a partial View of FIGURE 1 showing the difference in liquid level; and

FIGURE 3 is a schematic view of a modified pump arrangement of this invention.

As shown in FIGURE 1, the mattress 1 contain-s a first set of chambers 2, including the chambers 2a,.2b and 2c, and a second set of chambers 3, including the chambers 3a, 3b and 30. These chambers are formed between the folds of a flexible membrane A which is contained between upper and lower flexible watertight members. Two tube-like systems 2 and 3 are thus formed in this manner. The system 2 on one side is connected to a liquid supply pipe 4 and on the other side to the drain pipe 5. Likewise, the system 3 is connected on one side to the liquid supply pipe 6 and onthe other side to the drain pipe 7. A plurality of branch tubes 8 and 9 of the drain pipes 5 and 7, respectively, lead to the corresponding chambers.

Liquid supply pipe 4 extends to a pump 10 mounted within a liquid supply tank 11. A closed liquid flow United States Patent 0 3,317,934 Patented May 9, 1967 system thus extends from pump 10 through pipe 4, chamber system 2, and drain pipe 5.

Similarly, liquid supply pipe 6 for system 3 is joined to a pump 12 contained within a tank 13 to form a closed system by which liquid flows from pump 12 through pipe 6 and through chambers 3 and back through drain pipe 7 into tank 13.

A heat exchanger 14 is mounted in tank 11 and connected to a corresponding heat exchanger 14a in tank 13. These heat exchangers are supplied with either heated or refrigerated fluid.

Tanks 11 and 13 are also connected by pipes 15 and 16 to a reversible air pump B so that this pump can produce a higher than atmospheric pressure in one tank while causing a lower atmospheric pressure in the other tank. As shown in FIGURE 1, the air pump B has produced a higher pressure in tank 11 to depress the liquid to the level 17, while in tank 13, the liquid level 18 is raised. As shown in FIGURE 2, the pump has been reversed so that a less than atmospheric pressure produces the liquid level 19 in tank 11 and a greater than atmospheric pressure in tank 13 to form the liquid level 20. Thus, in FIG- URE l, the operation of the pump 10, with or without the use of the air pump B, will inflate the set of liquid chambers 2 while deflating or partially collapsing the set of liquid chambers 3. Reversal of the direction of pumps 10 and 12 will produce the opposite result, with or without. the use of air pump B, as shown in FIGURE 2.

In the modification of FIGURE 3, the pumps 10 and 12 have been replaced by a double-action piston pump, with each tank 11 and 13 being connected to a different cylinder in the pump. Thus again one set of liquid chambers can be inflated while the other set of chambers is being deflated and vice versa.

Thus the alternate inflating and deflating of the liquid chambers produces a pulsating effect in the bed mattress with the advantage of heat control in the mattress.

Having now described the means by which the objects of the invention are obtained,

I claim:

1. A change in pressure mattress comprising liquid impermeable flexible membrane means forming two separate adjacent sets of liquid receiving hollow chambers adapted to be alternately expanded and at least partially collapsed, tank means for supplying liquid to each set of chambers, reversible pump means associated with said tank means for forcing liquid into one set of chambers while withdrawing liquid from the other set of chambers and for recirculating the liquid through said chambers, and heat exchanger means in said tank means.

2. A mattress as in claim 1, said pump means comprising a double action piston pump having each cylinder thereof in communication with one of'said sets of chambers, respectively.

3. A mattress as in claim 1, further comprising gas pressure supply means joined to said tank means for alternately applying greater than and less than atmospheric pressure to the liquid in said tank means.

References Cited by the Examiner UNITED STATES PATENTS 2,245,909 6/1941 Enfiajian 5-348 2,965,372 12/1960 Cavanaugh 267-1 2,998,817 9/1961 Armstrong 5349 X 3,199,124 8/1965 Grant 5-349 DAVID J. WILLIAMOWSKY, Primary Examiner.

FRANK B. SHERRY, Examiner.

A. M. CALVERT, Assistant Examiner. 

1. A CHANGE IN PRESSURE MATTRESS COMPRISING LIQUID IMPERMEABLE FLEXIBLE MEMBRANE MEANS FORMING TWO SEPARATE ADJACENT SETS OF LIQUID RECEIVING HOLLOW CHAMBERS ADAPTED TO BE ALTERNATELY EXPANDED AND AT LEAST PARTIALLY COLLAPSED, TANK MEANS FOR SUPPLYING LIQUID TO EACH SET OF CHAMBERS, REVERSIBLE PUMP MEANS ASSOCIATED WITH SAID TANK MEANS FOR FORCING LIQUID INTO ONE SET OF CHAMBERS 